Lattice Boltzmann simulation of dense gas flows in microchannels

It is true that the Knudsen number that characterizes gas flows in microchannels increases to a finite value as the geometric dimension is reduced. However, since the gas in such a flow may retain a small mean free path and a small mean molecular spacing, the gas can still be rather dense in microdevices. Gas flows in microchannels have mainly been studied by molecular dynamics and direct simulation Monte Carlo methods. However, both methods are computationally expensive. In this work, we study dense gas flows in microchannels using an Enskog equation-based lattice Boltzmann Bhatnagar-Gross-Krook model. It is found that a dense gas flowing through a microchannel behaves different than a dilute gas under the same flow conditions.